/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package smalt.manager.ui.viewpage;

import android.view.ViewConfiguration;

/**
 * Helper for accessing features in {@link ViewConfiguration} introduced after
 * API level 4 in a backwards compatible fashion.
 */
public class ViewConfigurationCompat {
	/**
	 * Interface for the full API.
	 */
	interface ViewConfigurationVersionImpl {
		public int getScaledPagingTouchSlop(ViewConfiguration config);
	}

	/**
	 * Interface implementation that doesn't use anything about v4 APIs.
	 */
	static class BaseViewConfigurationVersionImpl implements
			ViewConfigurationVersionImpl {

		public int getScaledPagingTouchSlop(ViewConfiguration config) {
			return config.getScaledTouchSlop();
		}
	}

	/**
	 * Interface implementation for devices with at least v11 APIs.
	 */
	static class FroyoViewConfigurationVersionImpl implements
			ViewConfigurationVersionImpl {

		public int getScaledPagingTouchSlop(ViewConfiguration config) {
			return 0;
			// ViewConfigurationCompatFroyo.getScaledPagingTouchSlop(config);
		}
	}

	/**
	 * Select the correct implementation to use for the current platform.
	 */
	static final ViewConfigurationVersionImpl IMPL;
	static {
		if (android.os.Build.VERSION.SDK_INT >= 11) {
			IMPL = new FroyoViewConfigurationVersionImpl();
		} else {
			IMPL = new BaseViewConfigurationVersionImpl();
		}
	}

	// -------------------------------------------------------------------

	/**
	 * Call {@link ViewConfiguration#getScaledPagingTouchSlop()}. If running on
	 * a pre-{@link android.os.Build.VERSION_CODES#FROYO} device, returns
	 * {@link ViewConfiguration#getScaledTouchSlop()}.
	 */
	public static int getScaledPagingTouchSlop(ViewConfiguration config) {
		return IMPL.getScaledPagingTouchSlop(config);
	}
}
